Chain saws typically include an endless saw chain disposed to articulate around a saw bar. The saw chain generally includes various inter-coupled links, such as cutter links, drive links, and tie straps. Cutter links may be provided with a depth gauge in front of and slightly below a following cutting edge to substantially inhibit the cutter from taking an excessive bite or penetration into the wood. Excessive bite can occur particularly when there is contact between the chain at the upper quadrant of the bar nose and the material being cut (when cutting with the nose) or through accidental contact with a nearby branch or the like. Such contact may induce kickback.
Cutting speed is believed to be affected by the length and height and amount of free space in the gaps between the cutting teeth of the cutting links. When this space fills up the cutting teeth are forced away from the kerf bottom, i.e., out of the cutting mode. Particularly during a nose cut, the depth gauge of the cutting link will be pressed into the kerf bottom, thereby compressing the wood which allows the following cutting tooth to penetrate further into the kerf and take an undesired excessive bite that can cause kickback.
Cutting speed is believed to be further affected by the size and shape of the free space or gullet between the cutting teeth and the depth gauge of the cutting links. The gullet is a necessary space required in wood chip formation, transportation and egression from the cutting kerf. The gullet space may be optimized for cutting performance.